PAMTOPFM(1)

💖 pamtopfm — the Pamtopfm User Manual, bestie edition 💖

okay so you found the pamtopfm page in the General Commands Manual and you're like "what is this" — don't worry, I got you. sit down, grab a strawberry 🍓, and let's get into it.

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✨ NAME ✨

pamtopfm — Convert Netpbm image to PFM (Portable Float Map)

like. that's the whole vibe. it converts. it's giving translator but make it pixels. 💅

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🎀 SYNOPSIS 🎀

pamtopfm [-endian={big|little}] [-scale=float] [imagefile]

and before you come for me about the flags, some ground rules:

• All options can be abbreviated to their shortest unique prefix. yes bestie, you can be lazy, it's fine.
• You may use two hyphens instead of one. (--scale girlies rise up 🫶)
• You may separate an option name and its value with white space instead of an equals sign. the format police will not be called.

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🦋 DESCRIPTION 🦋

This program is part of Netpbm(1). iconic family. legendary lineage. 👑

pamtopfm reads a Netpbm image (PNM or PAM) and converts it to a PFM (Portable Float Map) image. simple as that, no notes.

The PFM (Portable Float Map) image format is a lot like PPM, but it uses floating point numbers with no maxval to achieve a High Dynamic Range (HDR) format. so like — glow up, but mathematically. ✨ That means it doesn't have a concept of absolute color, and it can represent generic light intensity information rather than just visual information like PPM does.

here's the example that lowkey makes it click: two pixels that are so close in intensity that the human eye cannot tell them apart are not visually distinct, so a visual image format such as PPM would have no reason to use different sample values for them. but an HDR format would. PPM is like "they look the same, who cares" and PFM is like "no actually, they're different and I will be respecting that." periodt. 💀

There are details of the PFM format in the "PFM Format Description" (1). go read it if you're that girl.

USC's HDRShop program and a program called Lefty use it. (shoutout to Lefty, whoever you are 🫡)

pamtopfm creates a color PFM image if its input is RGB (PPM) and a non-color PFM otherwise. it reads the room. it matches the energy. 🌈

Use pfmtopam(1) to convert a PFM image to Netpbm format — that's the reverse trip, the return journey, the round trip back home. 🔁

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💅 OPTIONS 💅

In addition to the options common to all programs based on libnetpbm (most notably -quiet, see Common Options), pamtopfm recognizes the following command line options:

• -scale=float — this specifies the scale factor of the PFM image. Scale factor is a component of the PFM format. Default is 1.0. that's the factory setting bestie, don't touch it unless you know why you're touching it.
• -endian={big|little} — this specifies the endianness of the PFM image. The samples in the raster of a PFM image are 4 byte IEEE floating point numbers. A parameter of the IEEE format, and therefore the PFM format, is endianness, i.e. whether the specified bytes are ordered from low addresses to high addresses or vice versa. big means big endian — the natural ordering; little means little-endian, the Intel-friendly ordering. Default is whichever endianness the machine on which pamtopfm runs uses internally, which results in the faster execution. it picks the one that's fastest for your machine because it's nothing if not efficient. 💅

ngl the endianness thing trips everybody up at first. it's just "which end of the number comes first," and your machine already has an opinion about it. the default is your machine's opinion. let it cook. 🍳

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👑 SEE ALSO 👑

Netpbm(1), pfmtopam(1), pam(1)

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🌸 HISTORY 🌸

pamtopfm was added to Netpbm in Release 10.22 (April 2004). vintage. retro. a classic that's still eating. 🎀

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📜 DOCUMENT SOURCE 📜

This manual page was generated by the Netpbm tool makeman from HTML source. The master documentation is at

http://netpbm.sourceforge.net/doc/pamtopfm.html

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and that's the whole page bestie!! 💖 this came to you straight from netpbm documentation, dated 10 April 2004 — yeah, 2004, we been knew, the lore is deep. now go convert something, you absolute icon. 🦋✨👑